Abstract: The hot deformation behaviour of two high-Mn (23-24 wt-%) TWIP steels containing 6
and 8 wt-% Al with the fully austenitic and duplex microstructures, respectively, has been
investigated at temperatures of 900-1100°C. In addition, tensile properties were determined over the
temperature range from -80 to 100°C. It was observed that in spite of the lower Al content, the
austenitic steel possessed the hot deformation resistance about twice as high as that of the duplex
steel. Whereas the flow stress curves of the austenitic steel exhibited work hardening followed by
slight softening due to dynamic recrystallisation, the duplex steel showed the absence of work
hardening and discontinuous yielding under similar conditions. Tensile tests at low temperatures
revealed that the austenitic grade had a lower yield strength than that of the duplex grade, but much
better ductility, the elongation increasing with decreasing temperature, contrary to that for the
duplex steel. This can be attributed to the intense mechanical twinning in the austenitic steel, while
in the duplex steel, twinning occurred in the ferrite only and the austenite showed dislocation glide.

Abstract: High silicon steel is used for electrical applications because its electrical resistivity is
increased and the magnetostriction is reduced. A silicon content up to 6.5 wt.-% gives excellent
magnetic properties. The improvement of the magnetic properties stays in contrast with the lack of
ductility of these alloys, making their thermo-mechanical processing difficult. The optimum final
microstructure and texture depends on the final application of the material: extremely big grains with a
Goss orientation ({110} <001>) are desired in transformers and grains with an average size of 100 -m
and cube component ({100} <001>) are used in electrical motors.
A series of plane strain compression (PSC) tests were performed on 3 electrical steels, with a silicon
content from 1.8 to 4.1 wt.-%, in a temperature range of 800 to 1100°C, strain rates between of 0.5 and
5 s-1. Reductions and time between deformation and quenching were also varied in order to study the
recrystallisation progress. Apparent activation energies for hot working, calculated using the hyperbolic
sine equation, was in good agreement with literature and higher than the activation energy for self
diffusion in iron. These values increase with the silicon content.
The high temperature texture evolution was investigated by means of electron back scattering
Diffraction (EBSD) technique, which allows the quantification of important texture components in
function of the thermo-mechanical parameters applied during hot rolling and the plane strain
compression tests. The hot rolled microstructures have shown an average grain size of 140 -m and a
texture with a maximum on the cube fibre ({001} ). The conventional α (<110> // RD) / γ
(<111> // ND) fibre texture was developed after plane strain compression and their intensities depend
on the deformation temperature and reduction. A similar tendency was observed for the fraction of
static recrystallised grains.

Abstract: Uni-axial tensile plastic deformation behavior of rolled magnesium alloy AZ31B under the temperature range from room temperature(RT) to 250°C with strain rates between 10-3 and 10-1s-1 has been systematically investigated. Microstructure evolution and texture were determined using optical microscopy (OM) and electron back-scattered diffraction (EBSD) techniques, respectively. Our results indicated that the strength and elongation-to-fracture were more sensitive to strain rates at elevated temperature rather than that at room temperature; dynamic recrystallization (DRX) and relaxation of stress at elevated temperature resulted in dramatic change of mechanical properties. Compared with strain rate, the temperature played a more important role in ductility of AZ31B Mg alloy sheet.

Abstract: The paper describes the mechanism of deformation at 77 K of pure aluminum bicrystals of different grain orientations. The following orientations were selected: {100}/{110} (cube/Goss) and - {100}/{100} (cube/shear) to represent the unstable vs. stable and the unstable vs. unstable behaviours, respectively. The bicrystalline samples were deformed in the plane strain conditions with the use of a channel-die immersed inside a reservoir with liquid nitrogen. The low temperature deformation increases the tendency to form plain strain inhomogeneities of the deformation in the grains with an unstable orientation. In both sets of crystallite compositions, the grain boundary was situated perpendicularly to the compression plane. A particular interest was paid to the analysis of the tendencies of the crystal lattice rotations near the grain boundary and the description of the deformation behaviour of the material in the macro- scale (hardening behaviour). A detailed analysis of the crystal lattice rotations was possible with the application of the local orientation measurements by means of scanning and transmission electron microscopes, equipped with the electron backscattered diffraction and convergent beam electron diffraction facility, respectively. The experimental results of the local orientation measurements were used to evaluate the accuracy of the numerical prediction of the macro-scale behaviour of bi-crystalline samples by a single Cristal Plasticity Model. The investigation shows that the crystallites behave essentially as single crystals in the same deformation conditions. Due to the similar hardening behaviour of the investigated crystallites (similar values of the Taylor factors) the grain boundary remains unchanged. The calculated lattice rotations are similar to those observed experimentally. Key words: aluminium bi-crystals, texture, microstructure, single crystal plasticity model